Pneumatic spring for vehicles.



C. R. PALMER.

PNEUMATIG SPRING FOB. VEHICLES. APPLICATION FILED DBO. 16, 1910.

Patented Jan.2,1912.

.IIIIIIIIIII .llllilll y CHARLES R. PALMER, F CINCINNATI, OHIO.

i l PNEUMTIC SPRING FOR VEHICLES.

Specification of Letters Patent.

Patented aan. 2,1912.

, pplication led December 16, 1910. Serial No. 597,673.

1 To all whom it may concern:l

Be it known that I, CHARLES R. PALMER, a citizen of the United States of America, and resident of Cincinnati, county of Ham- 5 ilton, and State of Ohio, -have invented cer tain new and useful Improvements in Pneumatic Springs for Vehicles, of which the following is a specification. e

This invention relates to supporting means for 'the body portion of automobiles, Amotor cars and other vehicles, and has for an object to produce pneumatic means for supporting the body portions of such vehicles on the -axles or frame of the vehicle. a A further Objectis to produce an air or pneumatic spring for vehicles, which is provided with means for preventing the dissipation of the operating pressure. A further object is to provide means -by varying the resiliency of` the pneumatic spring, to accommodate variations 1n the load on thevehicle.

These and other objects 'I attain by means of an apparatus embodying the featurei herein described, and illustrated in thvdrawings accompanying this application and forming a part thereof.

vIn the drawings, Figure is a partial rear elevation of a motor car provided with an embodiment of my invention; portions of the car are shown in section, for convenience of illustration. Fig. 2 is a sectional View of a pneumatic spring, which forms a part. of my invention, and which is shown 1n the compressed position. Fig. 3 is a section on tion and omitted the driving gears of the car.

The embodiment of my invention illustrated, consists of pneumatic springs 7,

which are located between the body 4 and the frame portion of the car and are in communication with one or more pressure tanks 8, which are `located on the body of the car. Each spring 7 consists of a cylinder 9, a piston 10, adapted to coperate with the cylinder, and a flexible tube or bellows 11, located within the cylinder, and connecting with the piping 12 by means 4of a pipe 13, which extends through an opening provided in the piston y10. The inner end of the pipe 13 is hermetically connected to the tube by an suitable means,'so as to prevent the lea age of air from the tube. Each plston 10 is secured to the body of the 65 carl by means of a bracket 13, yand each cyllnder 9 is secured near one end ef the axles 5 by means of a suitable ball and socket joint connection 14, or any other con nection which will permit of relative motion between the axle and the cylinder; The plping 12 communicates with the tanks 8.

A separate valve 15 is located between each tank 8 andthe piping 12, so that communication between t-he piping and one or all of the tanks may be shut olf, if desired. E ach tube 11 is initially distortedrby providlng encircling liber or fabric bands 16 at points along the length of the tube, which are so located that the tube will crease in symmetrical folds, when compressed by the piston 10. Each piston is provided with an integrally formed apron 17, Awhich projects downwardly around the outside of the cylinder 9, for the purpose of preventing dust and grit from entering the cylinder, and also for the purpose of guiding the plunger during its reciprocations relative to the cylinder.

In the drawings, I have illustrated the springs 7 betweenthe rear axle 5 and the body portion, direct-ly connected with the piping 12, and it will be understood thatv similar springs 7 are located between the body and the front -axle of the car, and that the tubes 11 of the front springs may be connected to the pping 12 by any suitable pipliing, or may be connectedt a separate tan I have provided means for limiting the relative motion between each axle 5 and the body of the car, which consists of metal straps 18, secured to the body, and guide pins 19 secured to the axles.l Each strap l8'is -so arranged, that it is loop'ed around 105 one of the axles 5, at a point adjacent to one of the supporting springs 7, and each pin 19 projects through an opening provided in one of the straps and 1s supported and secured in place at its lower end by means of a bracket-20 secured to the axle. The upper end of each -pin is also secured laxle 5.

axle 5 in an inclined position, with the left f rear Wheel on an obstruction in the. road, so that the left rear supporting spring 7 is compressed and the right supporting spring is extended. Figs. 2 and 4 respectively, illustrate the relative positions of the parts of the left and right rear springs.

During the ordinary operation'of the car, the tanks 8 are subjected to a predetermined air pressure and are all in open communication with the iping 12, consequently the tube 11 of each air spring is subjected to the air pressure in the tanks. Underethese conditions the. air ressure is effective in supporting the y of the car on 'the frame portion, and the resiliency of the compressed and conned air is employed in absorbing shocks and preventing the jolts and jars from reaching 'the body of the car.

I have provided several of the tanks 8, so that I can vary the resiliency of the pneumatic springs to correspond with variations in the load on the car. As the pistons 10 reciprocate relative to the cylinders'9 and compress the tubes 11, it is apparent that the pressure in the communicating air system is increased, and it is equally apparent that this increase of pressure will be greater if the internal volume of they air systel'nis relatively small as compared with the volume of each piston. I therefore decrease the number of tanks in communication with the piping 12, when the load on the car is increased, by shutting of one.l or more .of the valves 15. This decreases :the internal volume of the compressed-air system, so that the air pressure in' the system is materially increased, as the springs 7 are compressed. This increase in pressure, in eiect, increases the supporting strength o'f the springs 7, or

increases their power of resisting distortion.

o supporting springs.

5 springs illustrated, neither t As the load on the car is increased, the number of tanks 8 may be decreased byclosing the valves 15.

The load encountered by the front axle of a motor car or automobile is more const-ant than the load encountered by the rear axle, and, consequently, it may be desirable to control the resiliency of the front supporting spring'7 inde endently of the rear .his is accomplished by providing one or more separate compression tanks 8, which communicate with the front springs, and which are independent of the tanks 8 for the rear spil-ings. In the e cylinders 9,

ports, and, consequently, they are each capable ofreciprocating relative to the other. It will be apparent that the cylinders 9 may be mounted on the body of the car, and that the coperating pistons may be mounted on the axle, without depart-ing from my invention. The arrangement illustrated is advantageous, in that it prevents dust and -t from workig its way into the cylinder. One of the advantages of providlng the tube 11 in each of the pneumatic springs, is that the compressed a1r system is hermetlcally sealed and that the necessity of p roviding packed joints between reciprocating parts, is eliminated. Such joints are always With my invention there is no opportunity for the leakage of the operating air pressure, since all of the connections employed in the pressure system may,be air tight.

By employing my invention, solid or cushioned tires may be employed on the vehicle wheels and the same results will be obtained as if pneumatic tires were employed.

What I claim is y 1. In combination with a vehicle body and its supporting frame, pneumatic springs located between the body and the frame, pressure tanks communicating with said springs, and valves for varying the number of tanks communicating with said springs.

supporting frame of a vehicle, pneumatic springs located between said body and said frame andcomprising cylinders, compressible tubes located within said cylinders, and pistons located between said cylinders and adapted to'operate to`compress said tubes, a plurality of tanks communicating with communication between each tank and said tubes.

3. A pneumatic spring comprising a cylinder, a pistnlocated within said cylinder and provided-'with an integrally formed annular apron which surrounds said cylinder, a pneumatic bellows located within said cylinder below said piston, and a source of pneumatic bellows.

inder, a piston located within said cylinder, a pneumatic bellows-located within said cylinder below said piston, a source of pneumatic pressure communicating with said bellows, and meansfor varyin the effective operating pressure within sai bellows. 5. A- pneumatic 'spring comprising a cylginder, a pistonlocated within said cylinder, i a pneumatic bellows-located" within said cylinder below said piston, a plurality .of presf sure' tanks, means for connecting said tanks 'to said bellows, andimeans for varying the a source of diliculty and are apt to leak.l

saidl tubes, and valves for controlling the 4. A pneumatic spring comprising a cylnor the pistons 10 are mounted on fixed sup- 2. In combination with the body andthe y pressure communicating with said number of tanks in communication with said bellows. l

6. In combination with the body and supporting frame of a vehicle, pneumatlc `5 springs located between said body and said frame and comprising cylinders secured to said frame, pistons located within said cylnders and secured to said body, pneumatic bellows located within said cylinders below said pistons, a plurality of pressure tanks communicating with said bellows through passages formed in said pistons, and valves for varying the number of .tanks inoommunication with said-bellows.

CHARLES R. PALMER. Witnesses: I f v WALTER F. MURRAY,

E. W. McCAms'rEn.` 

